The present invention relates to an absorbent article provided with wing-shaped flaps which are wrapped around the crotch section of underwear upon securing the absorbent article onto the underwear.
Conventionally, as absorbent article (N) such as sanitary napkins, panty liners, vaginal secretion-absorbing sheets, and urinary incontinence pads, etc., for example as illustrated in FIG. 10, a configuration in which absorbent body (52) consisting of a cotton-like pulp, etc. interposed between liquid-impermeable backing sheet (50) consisting of polyethylene sheets or polyethylene-laminated non-woven fabrics, etc., and liquid-permeable surface sheet (51) consisting of non-woven fabrics or porous plastic sheets has been known.
As such type of absorbent article (N), in order to prevent displacement while in the state of being attached, for example there exists a configuration in which one or a plurality of strips of adhesive layer (53, 53) are formed on the non-skin contacting surface (outer surface), wing-shaped flaps (W, W) which extend outwards are integrally formed on both sides of the napkin main body in relation to the longitudinal direction thereof, and adhesive layers (54, 54) are provided on the surface of liquid-impermeable backing sheet (50) (outer surface) of these wing-shaped flaps (W, W).
In order to secure the absorbent article (N) onto underwear (60), as illustrated in FIG. 11, the underwear is worn on the body after absorbent article (N) is positioned on underwear (60) at a position corresponding to the crotch, the wing-shaped flaps (W, W) which protrude to the side are made to protrude further outwards than the underwear, and both wing-shaped flaps (W, W) are folded back at fold lines (RL, RL) to adhere to the outer surface of the crotch area of underwear (60) while wrapping around the crotch section of the underwear.
However, when folding back the wing-shaped flaps, if these were folded back carelessly, such could cause incorrect adhesion where only a single part is folded back and the adhesives adhere to each other to create wrinkles or a ridged area or where a wing-shaped flap is folded back halfway and the adhesives adhere to each other. In addition, in cases when the flaps are not being properly folded back at fold line (RL), the fold lines of the wing-shaped flaps are folded back in a diagonally bent manner, and this protruding section created where the flaps are folded back would cause problems such as discomfort around the legs and displacement of the absorbent article which may even lead to leaks, etc.
Therefore, a variety of means to increase the fixity of the wing-shaped flaps in relation to the underwear (hereinafter, also referred to as panties) have been proposed. For example, disclosed in Japanese Patent Publication No. 4641979 is an absorbent article having an absorbent main body, having an absorbing layer and a leakage preventing layer, and a pair of wing sections which are provided on both sides of the absorbent main body along the portion facing excretory area and are secured onto underwear by being folded hack towards the non-skin facing surface of the underwear, wherein the shape of each wing section of the pair is asymmetrical in relation to a lateral transverse line passing through the midpoint of the edge of the distal end on each wing section, each wing section of the pair is configured such that the rear to front angle of inclination of the rear edge of the wing in relation to the longitudinal axis of the absorbent main body is smaller than the rear to front angle of inclination of the front edge of the wing in relation to the longitudinal axis of the absorbent main body, the front edge of each wing of the pair is straight, and the rear edge of each wing of the pair is of a continuous wave shape.
In addition, disclosed in Japanese Unexamined Patent Publication No. 2009-125430 is an absorbent article with wing-shaped flaps which are formed on both sides of the section of the main body where an absorbent body is interposed between a liquid-permeable surface sheet and a liquid-impermeable backing sheet and are each secured by wrapping around the crotch section of underwear when being attached, wherein the wing-shaped flaps have a front edge profile line that extends outwards from the main body section and a rear edge profile line that extends outwards from the main body section, the angle formed by a line along the lateral direction of the absorbent article and the rear edge profile line is greater than the angle formed by a line along the lateral direction of the absorbent article and the front edge profile line, and the center of gravity of the wing-shaped flaps is offset to be on the front side of the center of the line where the base of each wing-shaped flap is connected to the main body section. Furthermore, it is also disclosed in this Japanese Unexamined Patent Publication No. 2009-125430 that the front edge profile line and rear edge profile line are wave-shaped, curved, or a combination of being both wave-shaped and curved.